Experiments on the hydraulics and swimming responses of juvenile Chinook Salmon encountering a floating guidance structure

Abstract

Floating guidance structures are intended to promote safe passage for juvenile salmon migrating downstream through reservoirs. However, the ability of an engineered structure to guide fish to safe passage has been primarily tested through large-scale implementation in reservoirs or in laboratory studies and computer simulations without live fish. Research is needed that integrates fluid mechanics with fish behaviour to study how hydraulic conditions around a guidance structure trigger swimming behaviours. In this study, an outdoor experimental channel was used to identify: (a) the hydraulic signature of a floating guidance structure and (b) changes in fish swim behaviour in relation to channel hydraulics. The flow field surrounding a guidance structure at two deployment angles was characterized using acoustic Doppler velocimeters. Swimming behaviours of juvenile Chinook salmon were recorded using underwater videogrammetry. A statistical method for behaviour change detection identified the most likely locations of swimming behaviour changes in fish as they first encountered the guidance structure. Finally, the locations of behaviour changes were compared to the hydraulics surrounding each guidance structure. Taken together, results indicated the fish did respond to the guide wall with behaviour changes, but did not distinguish between the two guide wall angles. While the two guide wall angles did produce statistically different distributions of hydraulic variables, the differences were small, potentially too small for the fish to produce a behavioural response. To inform the design of guidance structures, further work may clarify if swim responses vary with more aggressive wall angles and/or higher approach velocities, or if any contraction of flow and/or visual cue will produce similar behaviour responses. K E Y W O R D S environmental fluid mechanics, fish behaviour, fish passage, floating guidance structure, guide wall, hydraulics, reservoirs 1 | INTRODUCTION A smolt (seaward migrating juvenile salmonid) often has several routes for passing a dam, each with its own limitations. Of all passage routes at hydroelectric projects, turbines produce the highest rates of injury and mortality, which can be caused by high shear stress, turbulence, cavitation, decompression, blade strike, and mechanical wounding

Predicting near-term, out-of-sample fish passage, guidance, and movement across diverse river environments by cognitively relating momentary behavioral decisions to multiscale memories of past hydrodynamic experiences

“…Our study here advances past contradictions toward a consistent explanation worth evaluating further; that is, G M and A M play different roles near guidance structures. Here, we find that G M triggers V M attraction along booms which corroborates some findings in laboratory experiments (Swanson et al, 2020). Acceleration A M on the other hand acts to repulse salmon.…”

“…Water velocity gradient Dijkgraaf, 1963;Royce et al, 1968;Fausch and White, 1981;Kalmijn, 1988Kalmijn, , 1989Fausch, 1993;Fletcher, 1994;Hayes and Jowett, 1994;McLaughlin and Noakes, 1998;Braun and Coombs, 2000;Crowder and Diplas, 2000;Montgomery et al, 2000;Kemp et al, 2003;Goodwin, 2004;Goodwin et al, 2006;Sweeney et al, 2007;Nestler et al, 2008;Russon and Kemp, 2011;Abdelaziz et al, 2013;Vowles et al, 2014;Oteiza et al, 2017;Albayrak et al, 2020;Beck, 2020;Swanson et al, 2020;Zhu L. et al, 2021;Tan et al, 2022;Li et al, 2023 Turbulence MacKinnon andHoar, 1953;Pavlov et al, 1982;Pavlov and Tyuryukov, 1993;Skorobogatov et al, 1996;Coutant, 1998;Coutant and Whitney, 2000;Crowder and Diplas, 2000;Pavlov et al, 2000;Cada and Odeh, 2001;Coutant, 2001;Crowder and Diplas, 2002;Enders et al, 2003;Smith, 2003;Lupandin, 2005;…”

Instantaneous River‐Wide Water Surface Velocity Field Measurements at Centimeter Scales Using Infrared Quantitative Image Velocimetry

“…IR‐QIV is generally able to extract the instantaneous velocity field reliably and robustly, in addition to the mean velocity field. While measurements of mean surface velocity may be sufficient for many applications, including estimating discharge, other applications require instantaneous velocity measurements, such as studying fish behavior near structures (Romine et al., 2017; Swanson et al., 2020). Furthermore, by leveraging hydrodynamic theory it is possible to use the turbulence metrics calculated by IR‐QIV to estimate the velocity index (Johnson & Cowen, 2017b), bed stress (Johnson & Cowen, 2017a), vertical profile of turbulence intensities (Johnson & Cowen, 2020), and hence the local bathymetry and discharge (Johnson & Cowen, 2016).…”